This invention relates to corona discharge devices and more particularly to improved regulation of the deposition of charge on an electrophotographic imaging member.
There have been many attempts to stabilize and regulate the deposition of charge on an electrophotographic imaging member. Typical of these approaches is a power system comprising a high voltage power supply operated in some degree of constant current mode with a voltage limiting device connected between the corona screen terminals and ground. Other attempts to stabilize the operation of such systems have resulted in the introduction of auxiliary electrodes to sense a current that is proportional to the current to the ground plane and use this value to regulate the current to the ground plane. These systems have no way of predetermining what the ratio is between the sense current and the ground current. In addition, once this ratio is established for one set of operating conditions, there is no way to predict what the ratio will be for other operating conditions.
It is therefore the major objective of this invention to provide a control circuit for a corona discharge device in which the control parameters can be measured directly for control purposes.
It is another objective of this invention to provide a control circuit for a corona discharge device in which the control parameters can be accurately remotely controlled.